The increased use of automation in the metal-cutting industry has created a demand for effective means for providing on-line tool wear measurements. Suitable designed systems for continuously monitoring tool conditions during the actual operation of a machine should permit the use thereof by unskilled operators and the interfacing thereof with automatic machine tool control systems so that the machine can, in effect, monitor itself. Further, the wear on a tool plays an important role in determining how much time a machine must be shut down for tool changes. Moreover, premature wear or failure of a tool may cause several pieces which are being machined to be processed incorrectly, resulting either in their complete loss or a degraded quality. Accordingly, an effective on-line measurement of tool wear can permit better control of both operating costs and product quality in automated processes.
It is desirable to provide a tool wear monitoring system which is capable of providing an accurate and precise reading of tool wear during actual machine operation with a minimum of time delay in the tool wear detection process. Such a tool wear measurement device should provide high reliability at reasonable cost both in terms of its manufacturing and installation costs, as well as in its operating costs. The procedure for calibrating such a device should be relatively simple and automatic and consume minimal time of an operator who probably need not have maximum skills in the tool operating art.
Further, such a system should carry out its function without requiring changes in tool design that might adversely affect the cost of production. Such a device should provide minimum interference with the operating process for which the machine tool has been installed. Finally, such a system should be applicable in monitoring many different tools without modification either to the system itself or to the tools which are being monitored.